JP6728662B2 - Clutch control device - Google Patents

Description

The present disclosure relates to a clutch control device for controlling a clutch provided between an engine and an automatic transmission.

In a vehicle equipped with an engine as a power source for traveling, traveling is realized by transmitting an output from the engine to a drive wheel side via a transmission. As this type of transmission, an automatic transmission that automatically shifts gears according to the running state of the vehicle is widely used. For example, in a torque converter type automatic transmission, loss due to fluid viscosity and slippage is not a little generated, and therefore improvement of fuel consumption performance and acceleration performance is a problem.

For example, Patent Document 1 discloses a technique for improving fuel efficiency without causing deterioration in acceleration feeling when improving power transmission efficiency by adopting a lockup clutch in a torque converter type automatic transmission. ing.

JP, 2009-180361, A

In recent years, the demand for fuel efficiency of vehicles has been increasing due to increasing environmental awareness. In response to such a demand, in a vehicle equipped with an automatic transmission, when the vehicle is stopped in the running range, the clutch provided between the automatic transmission and the engine is disengaged, so that the engine in an idle state There is known a so-called idle neutral control for suppressing fuel consumption in the vehicle.

As described above, in vehicles equipped with an automatic transmission, improvement in fuel consumption performance and acceleration performance is a subject, but such a subject is not an exception even in a vehicle in which idle neutral control is adopted. On the other hand, generally, when priority is given to improvement of acceleration performance, fuel efficiency tends to decrease, and there is often a trade-off relationship between acceleration performance and fuel efficiency. Therefore, it is required to balance the acceleration performance and the fuel consumption performance in a balanced manner according to the acceleration demanded by the driver.

At least one embodiment of the present invention has been made in view of the above problems, and in a vehicle equipped with an automatic transmission that is connected to an engine via a clutch, provides good acceleration performance in accordance with a driver's required acceleration. An object of the present invention is to provide a clutch control device that can achieve both fuel efficiency performance.

(1) for the clutch control device according to at least one embodiment of the present invention to solve the above problems, a clutch control apparatus in a vehicle equipped with an automatic transmission connected to the engine via a clutch, the vehicle A vehicle speed detection unit that detects the vehicle speed, a required acceleration detection unit that detects the required acceleration of the vehicle, and a clutch control unit that controls the clutch, wherein the clutch control unit is configured such that the vehicle connects the clutch. When the vehicle speed is equal to or higher than a predetermined value, the clutch is temporarily controlled to be in a semi-engaged state, and thereafter, the acceleration detected by the required acceleration detection unit is a predetermined acceleration. Even if the rotation speed of the engine exceeds a predetermined value, the half-engaged state of the clutch is maintained, and the clutch is returned to the engaged state when the rotation speed of the engine exceeds a predetermined value .

According to the above configuration (1), while traveling at the output of the engine while the clutch coupling state, when a large acceleration than the predetermined acceleration is requested, the clutch control unit will temporarily half coupled state of the clutch To control. In the semi-coupled state, the load applied to the engine is smaller than in the coupled state, and the engine rotation speed can be easily increased (that is, the racing is improved). As a result, the acceleration performance of the vehicle is improved, and it becomes possible to favorably respond to a large acceleration request from the driver.
Further, when the vehicle decelerates in the high speed range, the clutch is prepared in the semi-engaged state in advance in preparation for the acceleration operation required for the subsequent reacceleration. As a result, when re-acceleration is requested, it is possible to quickly shift to the acceleration system, and as a result, good acceleration performance can be obtained during high-speed traveling.
Further, when the clutch is in the semi-engaged state and accelerated, control is performed so as to return the clutch to the engaged state at the timing when the rotation speed sufficiently rises. As a result, it is possible to prevent the clutch from being worn out due to the excessive increase in the rotation speed, and to improve the durability of the clutch.
It should be noted that although such an improvement in acceleration performance may be accompanied by a reduction in fuel efficiency performance in a considerable amount, in the present embodiment, by performing the clutch control only when the required acceleration from the driver is large, the fuel efficiency performance is improved. It is possible to improve the acceleration performance as necessary while suppressing the decrease of

( 2 ) In some embodiments, in the configuration of (1), the vehicle can select a first operation mode and a second operation mode in which acceleration performance is improved as compared with the first operation mode. In the second operation mode, the predetermined acceleration is set to be smaller than that in the first operation mode.

According to the above configuration ( 2 ), by using the predetermined acceleration smaller in the second operation mode than in the first operation mode, even in the case of a smaller required acceleration, the semi-coupled state as described above is obtained. Perform clutch control. Thereby, the acceleration performance in the second operation mode can be improved more effectively.

( 3 ) In some embodiments, in the configuration of (1) or (2) , the clutch control unit switches the clutch to the disengaged state when the vehicle is stopped in the traveling range. Thus, the clutch is controlled so that the idle neutral state is implemented.

According to the above configuration ( 3 ), the above control is applied to the vehicle that implements the idle neutral state by switching the clutch to the engaged state when the vehicle is stopped in the traveling range. As a result, it is possible to realize a vehicle capable of performing good acceleration in accordance with the acceleration demanded by the driver while improving fuel efficiency by performing idle neutral control when the vehicle is stopped.

According to at least one embodiment of the present invention, it is possible to provide a clutch control device capable of achieving both good acceleration performance and fuel efficiency performance in a vehicle equipped with an automatic transmission that is connected to an engine via a clutch.

It is a schematic diagram which shows roughly the structure of the vehicle which concerns on at least 1 embodiment of this invention. It is a block diagram which shows the internal structure of ECU of FIG. 3 is a flowchart showing clutch control executed by the ECU of FIG. 2 for each process. 5 is a time chart showing an example of changes over time in accelerator opening, slip amount, engine speed, and vehicle speed.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative positions, and the like of the components described as the embodiments or shown in the drawings are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. Absent.
For example, the expression "relative or absolute" such as "in a direction", "along a direction", "parallel", "orthogonal", "center", "concentric", or "coaxial" is strictly In addition to representing such an arrangement, it also represents a state in which the components are relatively displaced by a tolerance or an angle or a distance at which the same function can be obtained.
Further, for example, an expression representing a shape such as a quadrangle or a cylindrical shape does not only represent a shape such as a quadrangle or a cylindrical shape in a geometrically strict sense, but also an uneven portion or A shape including a chamfered portion and the like is also shown.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one element are not exclusive expressions excluding the existence of other elements.

1 is a schematic diagram schematically showing a configuration of a vehicle 1 according to at least one embodiment of the present invention, FIG. 2 is a block diagram showing an internal configuration of the ECU 28 of FIG. 1, and FIG. 3 is an ECU 28 of FIG. FIG. 4 is a flow chart showing the clutch control performed by each process, and FIG. 4 is a time chart showing an example of time transition of the accelerator opening, the slip amount, the engine rotation speed, and the vehicle speed.

As shown in FIG. 1, the vehicle 1 includes an engine 2 as a driving power source. The output shaft 2 a of the engine 2 is connected to the automatic transmission 6 via the torque converter 4. The torque converter 4 includes a pump impeller 4a connected to the output shaft 2a of the engine 2, and when the pump impeller 4a rotates with the rotation of the output shaft 2a of the engine 2, the torque converter 4 passes through a turbine via an automatic transmission field. The runner 4b is configured to be driven.

The turbine runner 4 b of the torque converter 4 is connected to the transmission mechanism 10 of the automatic transmission 6 via a clutch (forward clutch) 8. When the clutch 8 is in the connected state, the rotation of the turbine runner 4b is input to the speed change mechanism 10 via the clutch 8 and then transmitted to the drive wheels of the vehicle 1 via a differential gear (not shown). On the other hand, when the clutch 8 is in the disengaged state, the rotation of the turbine runner 4b is blocked by the clutch 8 and is not transmitted to the drive wheel side.

The speed change mechanism 10 is composed of a plurality of sets of planetary gear mechanisms and clutches and brakes that allow or restrict the operation of the components thereof, and the engagement state of these clutches and brakes is automatically supplied from a hydraulic power source. It is configured to achieve a desired shift speed by timely switching by a transmission field. In the present embodiment, a well-known structure is adopted as the detailed structure of the speed change mechanism 10, and in FIG. 1, components other than the clutch 8 as a friction engagement element are not shown.

The vehicle 1 detects an engine rotation speed sensor 12 for detecting a rotation speed Ne of the engine 2, a vehicle speed sensor 16 for detecting a traveling speed Vs of the vehicle 1, and an accelerator operation amount θ _ACC which is an accelerator opening degree. An accelerator sensor 20 and a brake switch 22 configured to be operable in conjunction with a brake pedal (not shown) are provided.

Further, in the vehicle 1, a plurality of ranges can be switched by a driver operating a shift lever (not shown). In the present embodiment, as such a range, a neutral range (N range), a drive range (D range), a parking range (P range) and a return range (R range) are prepared. In the N range, the transmission mechanism 10 is in the neutral state, and the power from the engine 2 to the drive wheels is shut off. In the D range, the gear position of the speed change mechanism 10 is automatically switched and controlled according to the traveling state of the vehicle 1, and the vehicle 1 can travel forward. In the P range, the parking brake is automatically operated to secure the stopped state of the vehicle 1. In the R range, the reverse gear of the transmission mechanism 10 is selected to allow the vehicle 1 to travel backward.

Any of these ranges is selected by the driver operating the shift lever. The range selected by operating the shift lever is configured to be detected by the shift position sensor 24 provided in the vehicle 1.

When the D range is selected by the shift lever, the vehicle 1 is ready to travel forward as described above. Here, in the D range, a first operation mode and a second operation mode are further prepared as operation modes. The first driving mode is a normal driving mode, and the second driving mode is a so-called sports driving mode in which the acceleration performance of the vehicle 1 is improved as compared with the first driving mode (for example, in the second driving mode, , The shift change timing is set to shift to the higher rotation speed side of the engine 2 or the response to the accelerator pedal of the engine 2 is improved as compared with the first operation mode).

The first operation mode and the second operation mode are configured to be selectable by the driver by operating the operation mode selection switch 26. When the driver selects the D range by operating the shift lever, for example, the operation mode selection switch 26 is initially set to the OFF state, but when the operation mode selection switch 26 is turned on by the driver, the second operation is performed. Switch to mode. This basically allows the vehicle to travel in the first operation mode, which is relatively excellent in fuel consumption performance, and to perform sports travel in the second operation mode as required by the driver.

The ECU 28 is a control unit of the vehicle 1 and includes the various sensors and switches described above (engine speed sensor 12, turbine speed sensor 14, vehicle speed sensor 16, accelerator sensor 20, brake switch 22, shift position sensor 24, and operating mode selection switch). Various processes required for the vehicle 1 are performed by appropriately performing processing based on input information acquired from (including 26) and transmitting a control signal according to the processing result to each component. As shown in FIG. 2, the ECU 28 implements an idle neutral control, and a required acceleration detection unit 30 that detects a required acceleration to the vehicle 1, a gradient detection unit 32 that detects a gradient of a road surface on which the vehicle 1 stops. A neutral control unit 34, a drive mode control unit 38 that controls the drive mode, and a clutch control unit 40 that controls the clutch 8 are provided.

The required acceleration detection unit 30 detects the required acceleration of the driver with respect to the vehicle 1 by acquiring the detection signal from the accelerator sensor 20. Further, the gradient detection unit 32 detects the road gradient θ by performing calculation based on various information acquired from the gyro sensor 35 and the navigation system 36 mounted on the vehicle 1, for example. A publicly known example will be followed as a specific calculation method of the road surface gradient θ in the gradient detection unit 32. For example, the angular velocity of the vehicle 1 detected by the gyro sensor 35 and the map information stored in the navigation system 36. The road surface gradient θ may be calculated by taking out the information about the road surface gradient corresponding to the GPS position information of the vehicle 1 from.

When a predetermined start condition is satisfied when the D range is selected by the driver's shift lever operation, the neutral control unit 34 starts idle neutral control for switching the clutch 8 to the disengaged state while maintaining the D range. In the present embodiment, the idle neutral control is set to be started when, for example, it is determined that the following conditions (a) to (c) are all satisfied.
(A) The brake switch 22 is on (brake on).
(B) The accelerator sensor 20 is off (accelerator off).
(C) The vehicle speed Vs detected by the vehicle speed sensor 16 is less than a predetermined value.

Such idle neutral control is continued until, for example, the following cancellation conditions (d) to (f) are satisfied.
(D) The brake switch 22 is off (brake off).
(E) The accelerator sensor 20 is on (accelerator on).
(F) The vehicle speed Vs detected by the vehicle speed sensor 16 is a predetermined value or more.
In the present embodiment, in particular, on the premise that the D range is maintained, if any one of the conditions (d) to (f) is satisfied, the cancellation condition is satisfied, assuming that the driver has the will to start, The neutral control is set to be released by connecting the clutch 8.

The travel mode control unit 38 selectively controls the travel mode in response to the ON/OFF operation of the operation mode selection switch 26 when the D range is selected by the driver's shift lever operation. Specifically, as described above, the first operation mode is selected when the operation mode selection switch 26 is in the off state, and the second operation mode is selected when the operation mode selection switch 26 is in the on state. Selected.

The clutch control unit 40 automatically controls the connection state of the clutch 8 according to the traveling state of the vehicle 1. In the present embodiment, in particular, the clutch control unit 40 is configured to be able to select three types of connection states of the clutch 8, that is, a disengaged state, a coupled state, and a semi-coupled state. Here, the semi-bonded state means an intermediate state between the disconnected state and the bound state. Strictly speaking, when switching the disconnection state and the binding state to each other, there are not a few states having an intermediate coupling degree instantaneously, but the semi-bonded state in the present description does not include such a state. , Which is positively realized as an intermediate state between the disengaged state and the engaged state by clutch control by the clutch control unit 40. Specifically, assuming that the bond degree in the broken state is 0% and the bond degree in the bonded state is 100%, the bond degree in the semi-bonded state can take an arbitrary bond degree between 0% and 100%. Further, the temporal transition of the degree of coupling in the semi-bonded state may continuously transition an arbitrary degree of coupling between 0% and 100% as time passes, or a constant degree of coupling may be maintained. You may change.

Next, the specific content of the clutch control performed by the clutch control unit 40 will be described with reference to FIG.

In the following, clutch control in the vehicle 1 traveling in the D range is selected, but general clutch control not described here will follow a known example. Is omitted.

First, the ECU 28 determines whether or not the running vehicle 1 is in a decelerating state (step S1). Here, the determination as to whether or not the vehicle is in the deceleration state is made based on the detection value Vs of the vehicle speed sensor 16, but in addition to or instead of this, the determination is made based on the operating states of the accelerator sensor 20 and the brake switch 22. You can go. Specifically, as such a case, for example, it is assumed that the driver releases the accelerator pedal to decelerate during traveling.

When the vehicle 1 is in the decelerated state (step S1: YES), the ECU 28 further determines whether the vehicle speed Vs is equal to or higher than the predetermined value Vs1 (step S2). Here, the predetermined value Vs1 is a determination threshold value for determining whether or not the vehicle 1 is traveling at high speed, and the determination is made by comparing with the detection value of the vehicle speed sensor 16.

When the vehicle speed Vs is equal to or higher than the predetermined value Vs1 (step S2: YES), the clutch control unit 40 controls the clutch 8 to be in the semi-engaged state (step S3). In the running vehicle 1, the clutch 8 is basically in the engaged state so that the engine 2 is dynamically connected to the drive wheels. However, when the vehicle is decelerating in the high speed range, By this step, control is performed so as to shift to the semi-coupled state.

After that, the clutch control unit 40 determines whether or not the driver has the intention of re-acceleration (step S4). The presence/absence of this re-acceleration intention is determined based on whether or not the required acceleration Ar acquired from the required acceleration detection unit 30 is larger than a predetermined threshold value Ar0 set in advance. Here, if there is no request for reacceleration from the driver (step S4: NO), the clutch control unit 40 waits until the reacceleration request is detected.

When the re-acceleration request from the driver is detected (step S4: YES), the clutch control unit 40 determines whether the required acceleration Ar detected by the required acceleration detection unit 30 is larger than a predetermined acceleration Ar1 which is a preset threshold value. It is determined whether or not (step S5). Here, the predetermined acceleration Ar1 is a threshold value that serves as a reference value when the control pattern of the clutch 8 is changed according to the magnitude of the required acceleration as described below, and is typically used for determining whether or not there is a re-acceleration intention. Is set to be larger than the predetermined threshold value Ar0.

When the required acceleration Ar is larger than the predetermined acceleration Ar1 (step S5: YES), the clutch control unit 40 controls the clutch 8 to maintain the half-engaged state (step S6). In such a semi-coupled state, the load applied to the engine 2 is relatively small, so the rotational speed of the engine 2 can be easily increased, and as a result, good acceleration performance can be obtained. As described above, while the clutch 8 is maintained in the semi-engaged state, the clutch control unit 40 monitors whether the engine rotation speed Ne is equal to or higher than the predetermined rotation speed Ne1 (step S7). That is, the clutch control unit 40 quickly increases the engine speed Ne by maintaining the clutch 8 in the semi-engaged state, and as a result, the engine speed Ne becomes equal to or higher than the predetermined rotation speed Ne1 (step S7: YES). ), and controls to shift the clutch 8 to the engaged state (step S8). As a result, it is possible to suppress wear of the clutch 8 due to an excessive increase in the number of rotations and improve the durability of the clutch 8.

On the other hand, when the vehicle speed Vs during deceleration is lower than the predetermined vehicle speed Vs1 (step S2: NO), the above-mentioned clutch control is not performed, and the traveling is continued while the clutch 8 remains in the initial engagement state. It

As described above, in the present embodiment, when the vehicle speed Vs during deceleration is high, the clutch 8 is temporarily brought into the semi-engaged state to obtain good acceleration performance. Here, the influence of such clutch control on the acceleration performance of the vehicle 1 will be described with reference to FIG.

First, as shown in FIG. 4A, a vehicle 1 that initially travels at an accelerator opening of 50% is assumed. Then, at time t0, the driver releases the accelerator pedal (that is, the accelerator opening is set to 0%), whereby deceleration is performed. Such deceleration continues until time t1 (see FIG. 4D). Then, at time t1, the driver further depresses the accelerator pedal (by setting the accelerator opening to 100%) to perform re-acceleration. In the following description, a period in which the accelerator opening is 50% is referred to as a period T1, a period in which the accelerator opening is 0% is referred to as a period T2, and a period in which the accelerator opening is 100% is referred to as a period T3.

With such a change in the accelerator opening, the slip amount of the clutch 8 changes as shown in FIG. 4(B). In the period T1, the slip amount is 0% because the clutch 8 is in the engaged state so that the power from the engine 2 is transmitted to the drive wheels. In the period T2, since the vehicle speed Vs during deceleration is equal to or higher than the predetermined vehicle speed Vs1 (see FIG. 4D), the slip amount is controlled by controlling the clutch 8 to be in the semi-engaged state in step S3. It is 50%. Then, in the period T3, the required acceleration Ar is equal to or higher than the predetermined acceleration Ar1 (because the accelerator opening degree is increased to 100% as shown in FIG. 4A), the clutch 8 is in the semi-engaged state. The engine speed increases while being maintained. Then, at time t2, the engine speed Ne reaches the predetermined speed Ne1 or more, so that the clutch 8 shifts to the engaged state, and the slip amount also returns to 0% accordingly.

In the vehicle 1 in which such clutch control is performed, it is confirmed that the acceleration performance is improved as shown in FIG. In FIG. 4(D), the change in vehicle speed when the clutch control is performed is shown by a solid line, and the change in vehicle speed when the clutch 8 is temporarily maintained in the engaged state from the period T1 to T3 is shown by a broken line. .. As is clear from FIG. 4D, it is shown that the acceleration performance is remarkably improved by performing the clutch control. This indicates that the acceleration performance is improved by temporarily maintaining the semi-engaged state by the clutch control.

Here, the predetermined acceleration Ar1 which is the determination threshold value in step S5 may be variable depending on the driving mode selected in the vehicle 1. For example, when the second operation mode is selected, the predetermined acceleration Ar1 is set smaller than when the first operation mode is selected. As described above, in the second operation mode, by using the predetermined acceleration Ar1 smaller than that in the first operation mode, the clutch control to the semi-engaged state is executed even for a small required acceleration. Thereby, the acceleration performance in the second operation mode can be improved more effectively.

As described above, according to the present embodiment, good acceleration performance can be obtained by temporarily controlling the clutch 8 to be in the semi-engaged state when a large acceleration is required during traveling. In particular, since such clutch control is performed only when the acceleration demanded by the driver is large, it is possible to improve the acceleration performance as necessary while suppressing the deterioration in fuel efficiency as much as possible.

At least one embodiment of the present invention is applicable to a clutch control device for controlling a clutch provided between an engine and an automatic transmission.

1 Vehicle 2 Engine 4 Torque Converter 6 Automatic Transmission 8 Clutch 10 Transmission Mechanism 12 Engine Rotation Speed Sensor 14 Turbine Rotation Speed Sensor 16 Vehicle Speed Sensor 18 Oil Temperature Sensor 20 Accelerator Sensor 22 Brake Switch 24 Shift Position Sensor 26 Driving Mode Selection Switch 28 ECU
30 Required Acceleration Detection Section 32 Gradient Detection Section 34 Neutral Control Section 35 Gyro Sensor 36 Navigation System 38 Driving Mode Control Section 40 Clutch Control Section

Claims (3)

A clutch control device in a vehicle equipped with an automatic transmission connected to an engine via a clutch,
A vehicle speed detection unit for detecting the vehicle speed of the vehicle,
A required acceleration detection unit for detecting the required acceleration of the vehicle,
A clutch control unit for controlling the clutch,
Equipped with
The clutch control unit,
When the vehicle is decelerating while the clutch is in the engaged state and the vehicle speed is equal to or higher than a predetermined value, the clutch is temporarily controlled to be in the semi-engaged state, and then the required acceleration detection unit Even if the acceleration detected at is greater than a predetermined acceleration, the semi-engaged state of the clutch is maintained until the rotation speed of the engine exceeds a predetermined value, and when the rotation speed of the engine exceeds a predetermined value. A clutch control device for returning the clutch to the engaged state . The vehicle is configured such that a first operation mode and a second operation mode in which acceleration performance is improved compared to the first operation mode can be selected.
The clutch control device according to claim 1, wherein the predetermined acceleration is set to be smaller in the second operation mode than in the first operation mode. The clutch control unit, when the vehicle is stopped while the drive range, the as idle neutral state by switching the clutch to disconnect state is performed, and controls said clutch clutch control device according to claim 1 or 2.

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